1. Field of the Invention
Aspects of the present invention relate to a method and apparatus for managing contents, and more particularly, to a content management method and apparatus for storing and playing back content received through broadcast signals.
2. Description of the Related Art
Presently, broadcasting systems are moving from an analog broadcasting system to a digital broadcasting system. Under a digital broadcasting environment, a gradual increase in a wide variety of digital multimedia service programs can be anticipated. Accordingly, techniques for effectively protecting and managing digital multimedia service providers' revenue and consumers' rights are being vigorously researched.
Digital data, in particular, can be easily and quickly copied and can be unlimitedly transmitted and distributed. In addition, even copied digital data provides flexibility in editing and composition without degrading the quality of the original digital data. In addition, recent developments in satellite-based or network-based data transmission technology would be a benefit to users because they can maximize a users' convenience by efficiently providing a variety of multimedia services, such as music or video services, to users. However, these technologies also pose a problem to service providers or copyright holders because they make it more difficult to stably provide multimedia content to users. This is especially true when considering that an increasing number of literary, musical, dramatic, or artistic works have been digitalized and digital data can be easily copied, edited, and distributed illegally using personal computers. Accordingly, additional research on the protection of copyrights of multimedia content is greatly needed.
Digital broadcasting is characterized by providing multiple channels, high-quality broadcast programs, and multiple functions. The development of multiplexing technology has enabled video, audio, and other data to be transmitted together, regardless of their contents and sizes. Further, multiplexing technology enables interactive services to be provided to many viewers through the formation of return channels based on modems. Accordingly, digital broadcasting can overcome restrictions of conventional analog broadcasting and can provide high value-added multimedia services to viewers. However, unless a desired level of security is established between a sender and a receiver of digital broadcasting, the current commercial base of digital broadcasting may collapse.
Broadcasting businesses anticipate that they will be able to break from conventional ways of doing business, such as depending on advertisement revenues. These businesses anticipate that they can provide high-quality broadcasting services to their subscribers by increasing the number and variety of channels and will be able to collect subscription fees from the subscribers for high-quality pay programs according to either a pay-per-time method or a pay-per-view method. In addition, broadcasting businesses also expect various multimedia data that they transmit to be received only by authorized subscribers. In order to solve all these problems, a conditional access system (CAS) has been developed.
In the CAS, a user of a set-top box is authenticated on a per-program basis by the CAS. Once authenticated, the set-top box is allowed to watch a pay program. In this manner, a per-program charging policy can be realized. Specifically, a user is entitled to watch a predetermined pay program or any pay programs for a predetermined amount of time if he or she pays an appropriate subscription fee. If the user's subscription right expires, the user is not able to watch pay programs unless he or she pays for them again.
To meet more sophisticated, highly versatile user demand, however, there is a need for a technique of storing authorized contents in a user's content storage apparatus and playing back the same from the user's content storage apparatus. Accordingly, a content management method for protecting pay contents is desirable.